Markets fall. They always have, and always will. And every time they fall meaningfully, a predictable share of investors move their savings out of growth assets and into cash, usually within weeks of the bottom. They lock in the losses. Then, months later, they watch the recovery from the sidelines.
This is not a failing of intelligence. It's how humans are wired. Understanding the wiring is the first step to not falling for it again.
Two instincts working against you.
Loss aversion. Humans feel losses roughly twice as strongly as equivalent gains. When your retirement fund drops 20%, the emotional intensity is closer to losing 40%. Acting on that feeling rarely produces a good decision.
Recency bias. Whatever has been happening recently feels like what will continue to happen. A few bad months can persuade a calm brain that markets are "different this time". They almost never are.
What actually helps.
Automate the contributions. If a monthly debit order is investing new money through the downturn, you're buying shares at a discount without having to decide to do it. The discipline is the system, not your willpower.
Don't watch daily. Retirement money is a 20-year project. Checking it every day gives you 2,000 emotional events per decade, most of them noise. A quarterly check-in is plenty.
Write down your plan, before you need it. A one-page "if X happens, I will do Y" document, written on a calm day, is worth a lot when the panic hits. "If the market falls 20%, I will do nothing" is a legitimate, defensible plan. Having it on paper stops you rewriting it in the moment.
The best investor in your life is probably the version of you that already made the decisions, not the version reading the news at 10pm.